Which of the following is NOT classified as a macromineral?

Iron is classified as a trace mineral rather than a macromineral. Macrominerals are minerals that are required by the body in larger amounts, typically greater than 100 milligrams per day. These include calcium, potassium, and magnesium, which play vital roles in various bodily functions such as bone health, fluid balance, and muscle function.

In contrast, iron is needed in smaller amounts, usually around 8 to 18 milligrams per day, depending on factors like age and sex. It is essential for the formation of hemoglobin in red blood cells, but its lower required intake classifies it as a micromineral or trace mineral. Understanding the distinctions between macrominerals and trace minerals is crucial for nutritional science, as it informs dietary recommendations and understanding of nutrient roles in health.